/**
 * Copyright (c) 2009/09-2012/08, Regents of the University of Colorado
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/**
 * Copyright 2012/09-2013/04, University of Massachusetts Amherst
 * Copyright 2013/05-Present, IPSoft Inc.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License. 
 */
package com.googlecode.clearnlp.classification.feature;

/**
 * Feature token.
 * @since v0.1
 * @author Jinho D. Choi ({@code jdchoi77@gmail.com})
 */
public class FtrToken
{
	/** The source of this token. */
	public char   source;
	/** The offset from {@link FtrToken#source}. */
	public int    offset;
	/** The relation to {@link FtrToken#source}. */
	public String relation;
	/** The feature field. */
	public String field;
	
	/**
	 * Constructs a feature token.
	 * @param source the source of this token.
	 * @param offset the offset from the source.
	 * @param relation the relation to the source.
	 * @param field the feature field.
	 */
	public FtrToken(char source, int offset, String relation, String field)
	{
		this.source   = source;
		this.offset   = offset;
		this.relation = relation;
		this.field    = field;
	}
	
	public boolean isField(String str)
	{
		return field.equals(str);
	}
	
	public boolean isRelation(String str)
	{
		return relation.equals(str);
	}
	
	public String toString()
	{
		StringBuilder build = new StringBuilder();
		
		build.append(source);
		
		if (offset != 0)
			build.append(offset);
		
		if (relation != null)
		{
			build.append(AbstractFtrXml.DELIM_R);
			build.append(relation);
		}
		
		build.append(AbstractFtrXml.DELIM_F);
		build.append(field);
		
		return build.toString();
	}
}
